gillcalc Blog
Long-form aquarium guides: the reasoning behind the calculators, with sources and confidence grades.
- Fish Tank Size Calculator: How to Choose the Right Tank () — There is no honest fish tank size calculator lookup — here is how experienced keepers actually size a tank, from footprint to adult fish length.
- Aquarium Volume in Gallons: Nominal vs True, US vs UK () — A 55 gallon tank rarely holds 55 gallons. Why nominal sizes run 10 to 20 percent over true water volume, and how US and UK gallons differ.
- How Many Fish in a 20 Gallon Tank? Honest Stocking Numbers () — A 20 gallon is the classic first tank — but the stocking answer is a footprint question, not a gallon count. Community-caliber numbers by species, and the filter rule behind them.
- Fish Tank Size for Goldfish: By Variety, With Real Minimums () — Fancies and commons differ by a factor of three in tank size. Variety-by-variety minimums, why footprint beats gallons, and why the growth-stunting myth keeps bowls alive.